1. The field of art to which the invention pertains comprises the art of manual drive mechanisms for hand operation of a gasoline dispenser.
2. Except in rare instances, gasoline dispensing pumps throughout the world are electrically powered. Failure, however, to provide for manual operation in the event of a power disruption can cause the dispenser to remain idle for extended time periods, however long the power disruption continues. Consequently, it is not uncommon, particularly in remote areas in which power failures occur with some degree of frequency, to provide backup capability whereby a hand drive can be utilized to manually operate the dispenser in the absence of electrical power. Exemplifying equipment for that purpose is the disclosure of U.S. Pat. No. 2,898,002.
A characteristic construction of a prior art hand unit for operating gasoline dispensing pumps has been a separate hand drive for each pump unit within the dispenser to be adapted for manual operation. For a double pump dispenser, two manually operated devices have been employed for operating one or the other of the two pump units. While this arrangement has been generally satisfactory, it represents a duplication of equipment and is regarded as suitable where no more than two available octane choices are to be selected by the customer. Complicating this prior art approach are blend-type dispensers in which a separate high and low octane pumping unit can be set either to operate independently of each other or simultaneously together for dispensing a variety of different blends of intermediate octane. For the latter, such individual hand units have been recognized as highly impractical. Yet despite recognition of the problem, a single hand apparatus readily operable in the various operational modes of a blend-type dispenser has not been previously known.